The treatment of human skin with various agents has been undertaken for many years with the goal being to keep the skin clean and in a smooth and supple condition. Skin has the tendency to dry out when exposed to low humidity or to harsh detergent solutions for extended periods of time. From a physiological standpoint, dryness is a measure of the water content of the skin. Under normal conditions, the water content and vapor pressure of the skin are higher than those of the surrounding air, with consequent evaporation of water from the skin's surface. Skin becomes dry because of excessive loss of water from its surface, which results in loss of water from the stratum corneum. Low humidity speeds up this process, exacerbating the drying of skin. Also, continuous and prolonged contact with or immersion in soap or detergent solutions can contribute to dryness of the stratum corneum. The reason for this is that these solutions promote dissolution of the skin surface and lipids, and the dissolution of the hygroscopic water-soluble components of the skin.
Also, in normal skin, the stratum corneum is shed as individual cells or as small clusters of cells. Skin problems such as dry skin, psoriasis, ichthyosis, dandruff, acne, callus, photodamaged skin, aged skin, and sunburn can be described as disorders of keratinization in which the shedding of stratum corneum cells at the skin surface is altered relative to normal, young, healthy skin. Such alteration results in shedding of large clusters of cells leading to visible scaling of the skin, a build-up of keratinaceous material on the surface or in follicles or ducts, and a rough texture to the skin surface. These conditions can be improved by removal of the outermost keratinaceous material. In other words, by desquamation.
Additionally there is an ongoing need to effectively deliver a wide variety of active ingredients to the skin, either via direct application of such a composition, or in the case of a cleansing composition, via the cleansing process.
Therefore, there is a need for topical skin care compositions which give the skin a smooth and elegant skin feel, which are useful for treating dry skin, and which are useful for providing a desquamation benefit. There is also a need for providing cleansing products have these attributes. There is also a need for composition which are also useful for delivering a wide variety of active ingredients to the skin, either directly to the skin or during the cleansing process.
It has been found in the present invention that skin care compositions containing a combination of amphoteric surfactants, anionic surfactants, and cationic surfactants are useful for providing these skin care benefits.
It is therefore an object of the present invention to provide skin care compositions for topical application to the skin.
It is another object of the present invention to provide skin care compositions having improved skin conditioning properties, and which are also mild and nonirritating to the skin.
It is another object of the present invention to provide skin care compositions which improve skin dryness and which give the skin a smooth, soft, silky feel.
It is another object of the present invention to provide skin care compositions which are useful delivering a wide variety of active ingredients to the skin.
It is another object of the present invention to provide skin care compositions, which, when in the form of cleansing compositions, are useful for delivering a wide variety of active ingredients to the skin via the cleansing process.
It is another object of the present invention to provide methods for treating the skin.
It is another object of the present invention to provide methods for cleansing the skin, for clarifying the skin, for reducing skin dryness, for reducing pore size, and for delivering active ingredients to the skin.
It is another object of the present invention to make the skin feel soft and smooth.
These and other objects will become readily apparent from the detailed description which follows.